With a view to obviating the need for wired cabling connections between stations in local area networks (LANs), wireless local area networks have been developed and are now commercially available. However, the coverage area of wireless LANs is restricted especially in an indoor environment, due to the presence of structural features such as walls and floors in buildings, for example. Also, it may be desirable for stations in a wireless LAN to communicate with remote facilities or resources such as servers. Therefore, it has been proposed to connect the wireless LAN via a bridging means to a wired LAN, which can be connected to the remote facilities and/or other wireless LANs.
One problem with implementing wireless LANs is to provide a suitable access protocol for stations desiring access to the wireless transmission medium. One known standard protocol utilized in wired LANs is CSMA/CD (carrier sense multiple access with collision detection). However, the CSMA/CD protocol cannot be satisfactorily implemented in a wireless environment because of the very high dynamic range of the signals on the wireless medium. One protocol which has been successfully implemented in a wireless environment is a CSMA/CA (carrier sense multiple access with collision avoidance) type of protocol. Such a protocol does not guarantee collision-free operation and it is still possible for packets on the wireless medium to be lost, especially during times of high traffic load. Also, interference may derive from other causes, such as other nearby networks using the same frequency band, or sources which generate frequency components in the band. Such interference also may affect the reliability of packet transmission in a wireless LAN.